ES2555305T3 - Reinforcement layer for vehicle tires - Google Patents

Abstract

Reinforcement layer (13) for vehicle tires, preferably for the tread band (8) or belt (7) of a tire, comprising at least one reinforcement support embedded in an elastomeric material (10) which has a plurality of monofilaments (11), characterized in that a plurality of monofilaments (11) of the reinforcement support are basalt fibers.

Description

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DESCRIPTION

Reinforcement layer for vehicle tires

The invention relates to a reinforcement layer for vehicle tires, preferably for the tread band or a tire belt comprising at least one reinforcement support embedded in an elastomeric material having a plurality of monofilaments . The invention also relates to a tire comprising, at a minimum, a reinforcing layer according to the invention, especially in the form of a reinforcing layer of the belt and / or tread band.

The person skilled in the art knows different models of reinforcement supports for the reinforcement layers of tires made of different materials and shapes. A reinforcement support, at a minimum, of a reinforcement layer of this type is embedded, for example by calendering, in a mixture of elastomer so that it can be used as a reinforced reinforcement layer in the tire.

A "thread" is a linear structure of one or more fibers or one or more filaments. By "monofilament" is meant, in the sense of the application, a thread composed of exactly one filament or exactly one endless fiber or also a twist of twisted fibers of limited length. Accordingly, a thread may be formed by one or more monofilaments. A "cord" fabric is a filamentous product composed of one or more threads subjected to a final twist.

Until now, textile-based reinforcement brackets are being used as reinforcement of the tread band, in terms of their primary material, in the fossil oil raw material, such as PET (polyethylene terephthalate) , aramid or nylon or hybrid cord fabrics of these threads. Also known is the use of reinforcement supports not based on oil and made of viscose such as rayon or Lyocell, which are based on the cellulose raw material that grows again.

The drawback of materials based on raw materials that grow back as a material for textile reinforcement supports consists in the fact that they have no endless filamentous structure, but strong variations in fiber quality.

The lack of contraction further hinders the special use of rayon as a reinforcement support in the tread band. Another disadvantage of the rayon is that the rayon is sensitive to moisture, whereby the breaking strength of the reinforcing support is reduced as a result of moisture absorption. As if that were not enough, the acquisition of rayon is a very high cost.

Steel cord fabrics based on iron raw material are normally used as reinforcement support for the tire belt. In this case, the drawback lies in the high specific weight.

Development involves optimizing products, not only with a view to their properties, but also with a view to the raw materials used. The availability of raw materials acquires special importance. Therefore, it is about developing and providing products that renounce usual raw materials such as iron or oil, which are in high demand but with limited availability, without having to accept, for example, losses in the duration of tires or in the resistance of cord fabric of the products manufactured with them.

From the presentation report JP 2008-291395 A, a drive belt with a tension cable containing basalt filaments is known. However, nothing is said in the report of the suitability of a use of basalt fibers as a component part of reinforcement layers of the belt or of the tread of the tire tread.

The present invention is based on the task of providing a reinforcement layer, especially for the tread and / or the tire tread of a tire, the reinforcement support being manufactured, at least one and at least in part, of a non-oil based material, not iron based and not cellulose based, but available on a large scale. At the same time it is intended that the reinforcement layer has a constant product quality.

This task is solved by the fact that a high number of the monofilaments of the reinforcement support corresponds to basalt fibers.

Surprisingly, basalt fibers are very suitable as a component of the reinforcement brackets of the belt and / or the tread band of the tires.

Reinforcement brackets containing basalt fibers have advantageous properties compared to the reinforcement layers of usual fiber materials. In comparison with steel, they exhibit especially an advantageous compression behavior and, for example, in comparison with nylon, a high modulus of elasticity. In comparison with textile materials, basalt also shows an advantageous thermal stability as well as an advantageous chemical resistance.

On the other hand, basalt, as raw material, is available on a large scale. Basalt material is an alkaline volcanic eruptive rock and, therefore, a primary raw material. Like oil, basalt raw material cannot be renewed rightly by humans. However, basalt is the most volcanic rock

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frequent and, therefore, a natural raw material from an easily accessible and practically inexhaustible source. In addition, nature reproduces basalt as a result of volcanic activity and internal movement of tectonic plates. For this reason it is not expected that this raw material will be scarce.

Basalt fibers are mineral fibers that are manufactured at high temperatures from molten basalt and which can then be transformed, for example, into cord yarns or fabrics. Basalt is an alumosilicate that contains, for example, aluminum oxide, silicon dioxide, calcium oxide and magnesium oxide. The exact chemical composition of the natural raw material is determined geologically and depends on the place of extraction. To adjust and optimize the product characteristics of basalt fibers in a defined way, basalts of different chemical composition can be combined and / or added to molten basalt, in addition to natural basalt, other additives.

"Basalt fiber" means in the sense of the application the endless basalt fiber, so it is a monofilament. In the reinforcement layer it extends essentially over the entire length of the reinforcement support.

Basalt fibers are considered not harmful to health. Basalt fibers can be recycled and have a positive price-performance ratio.

With a reinforcement layer with reinforcement brackets containing basalt fibers, therefore, an advantageous reinforcement layer for tires is provided, especially for the tread band or tread, which is not based primarily on materials Oil, iron or cellulose base. Basalt fibers can also be manufactured with a constant quality and provided at all times with the same product quality.

The basalt fibers of the reinforcing support can all have the same chemical composition. However, the reinforcing support may also contain a plurality of basalt fibers of a chemical composition, as well as a plurality of basalt fibers of another chemical composition. By "plurality of" is meant a number of at least 20. The monofilaments of a reinforcing support can also be differentiated in their fineness. By combining different monofilaments you can combine and take advantage of its different positive properties.

In an improved variant of the invention, basalt fibers are expected to contain at least 90% by weight, especially 95% by weight, especially 100% by weight, of natural basalt. The percentage by weight (% by weight) refers to pure basalt fiber, that is, basalt fiber without an optional functionalization and without an optional adhesive agent. As a consequence, a reinforcing layer can be provided whose reinforcement support, at least one, is formed, in whole or in part, by a raw material available on a large scale and not based primarily on oil, iron or cellulose.

In another advantageous improved variant of the invention it is provided that the monofilaments of the reinforcement support are basalt fibers. The reinforcing supports of the prepared reinforcing layers are therefore based, in whole or in large part, on the basalt raw material available on a large scale, and not primarily on oil, iron or cellulose, and they are always always available. In the same product quality.

In another advantageous improved variant of the invention it is provided that the reinforcement support has a plurality of monofilaments of a non-basaltic material. Accordingly, the reinforcing support has both a plurality of basalt fibers and a plurality of monofilaments of non-basaltic material. The non-basaltic material can be selected from the group containing polyester (PE), polyamide (PA), aramid, Arselon, polyether ketone (PEK), polyether ether ketone (PEEK), polyketone (POK), rayon, viscose, chemical fibers, natural, glass and / or carbon. In the case of polyamides, polyamides PA 4.6, PA 6, PA 6.6, PA 10.10, PA 11 and / or PA 12 can be used. In the case of polyester, it can be polyethylene polyethylene (PEN), polybutyleneterephthalate polyesters (PBT), polybutylene naphthalate (PBN), polypropylene terephthalate (PPT), polypropylene naphthalate (PPN). polyethylene terephthalate (PET), High-Modulus Low-Shrinkage-PET (HMLS-PET), especially thermoplastic polyester and / or crosslinked unsaturated polyester. Enumerations that include "and / or" are to be understood so that all elements of the enumeration are coupled with and / or. Due to the use of different materials, the properties of the different materials can be successfully combined and the characteristics of the reinforcement layer advantageously adjusted.

In an advantageous improved variant of the invention it is provided that the reinforcement support has a plurality of monofilaments of raw materials that grow completely or at least in part, especially of chemical fibers based on cellulose and / or natural fibers. In the case of chemical fibers based on cellulose, rayon and Lyocell can be mentioned in particular. In the case of natural fibers, wool (keratin) can be especially mentioned. Therefore, a reinforcement layer can be provided in which the monofilament material of the reinforcement supports is based entirely or in part on basalt as well as on re-growing raw materials, renouncing all or part of materials. based on oil, iron or cellulose. Another advantage consists in the possibility of adapting the reinforcement support properties correctly through the selection of materials.

In an improved advantageous variant of the invention, it is provided that basalt fibers are provided with epoxy and / or vitilic functionalization. In this way, reliable adhesion between basalt fibers and the bonding agent can be achieved.

In an improved advantageous variant of the invention, it is provided that the reinforcement support has a cord fabric of at least one thread, this thread having a plurality of basalt fibers. As a consequence a layer is created

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of reinforcement especially suitable as a reinforcement layer of the tread band and / or the tread band of a tire, whose reinforcement support, at least one, is composed, at least in part, of a non-material Oil based, not iron based or not cellulose based, but available on a large scale.

It is advantageous that at least one cord of the cord fabric is formed by basalt fibers. It is also advantageous that all the threads of the cord fabric are made of basalt fibers.

Advantageous is a fineness of yarn from 250 to 5000 dtex and a final twist of the twisted material with 25 to 600 t / m. It is also advantageous for the cord fabric to have two or more threads.

The at least two wires of a reinforcement support can be differentiated, for example, in the direction of twisting and / or in the number of twisting processes and / or in the title and / or fineness. In this way, the properties of the reinforcement support can be adjusted correctly.

It is appropriate that the cord fabric has at least one thread having a plurality of basalt fibers as well as a plurality of monofilaments of non-basaltic material, especially non-basaltic material of the aforementioned group.

Another advantage is that the cord fabric has at least one thread of basalt fibers as well as at least one thread of non-basaltic material, especially non-basaltic material of the group mentioned. It can be, for example, a cord fabric of a basalt fiber thread as well as another PE thread, especially PET or PEN, or another polyamide thread, especially PA 6.6, PA 6 or PA 10.10, or other Aramid wire, Arselon, PEK or POK. Also advantageous is a cord fabric of a basalt fiber yarn as well as another rayon thread, Lyocell or natural fibers.

Thanks to the use of different materials, the advantages of the different materials can be combined by optimally exploiting them through the geometric effect of torsion. The properties of the cord fabric can be adjusted accordingly.

In another variant of advantageous embodiment of the invention, it is provided that the reinforcement support is a belt whose cross section meets the condition a <b, defining the height of the cross section and b the width of the cross section of the tape, that the tape is arranged in the reinforcement layer so that the direction of extension of b is oriented approximately parallel to the surface extension of the reinforcement layer, that the tape contains a plurality of monofilaments arranged parallel to the longitudinal extension of the tape , the monofilaments being held together within the tape by means of the bonding agent, and that a plurality of the monofilaments be basalt fibers. The monofilaments are arranged essentially in the direction of the longitudinal extension of the tape. They do not twist each other specifically, but are mostly arranged, at least in sections, in parallel, and it is also possible for the monofilaments to cross. The reduced height of the cross section a as well as the width of the cross section b of the belt is achieved through the arrangement of the monofilaments located essentially parallel in the direction of the extension of the width of the cross section b. The tape itself is also not arranged in the reinforcement layer with a specific twist. Each monofilament is attached by means of an adhesive agent and is attached with this adhesive agent, at least in sections, to other monofilaments of the tape.

The important thing is that, thanks to the use of very flat cross-section tapes as a reinforcement support, a short height reinforcement layer is provided. This results in a minor hysteresis. As a result of saving elastomeric material as well as reinforcement support material, hysteresis as well as weight are reduced. Due to such a flat reinforcement layer, when used in tires, a reduction in the rolling resistance of the tire is achieved.

It is convenient that the tape has a fineness of 50 to 7000 dtex, preferably 500 to 3500 dtex, especially preferably 1200 to 1500 dtex, and that the tape has a number of 25 to 4500 filaments, preferably a number of 450 to 2000 filaments, especially preferably a number of 500 to 1200 filaments. It is also convenient that the height of the cross section meets the condition of 1 ^ m <to <1500 ^ m, preferably 1 ^ m <to <500 ^ m, especially preferably 1 ^ m <to <200 ^ m. It is advantageous that the width of the cross section b meets the condition of 100 ^ m <b <15000 ^ m, preferably 300 ^ m <b <10000 ^ m, and that the ratio between the cross section's width and the height of the cross section a meets the condition of 4000> b / a> 1.5, especially 200> b / a> 3.5, especially 19> b / a> 6.5.

It is advantageous that the tape bonding agent is a crosslinkable resin, a liquid thermoplastic resin, a wax or a substance, for example of the RFL type (Resorcinol-Formaldehyde-Latex), which can interact with elastomeric material. It is also advantageous that the bonding agent hardens and is in the tape in the hardened state. Another advantage is that the tape also has a plurality of monofilaments of non-basaltic material.

It is convenient to activate the surface of the reinforcement support mechanically, physically and / or chemically to ensure adhesion between the reinforcement support and the adherent impregnation or between the reinforcement support and the elastomeric material.

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To ensure reliable adhesion between the reinforcement support and the elastomeric material, it is convenient to provide the basalt fibers and / or the reinforcement support additionally with an adherent impregnation, for example of RFL-Dip, by the 1 or 2 bath procedure.

The invention also relates to a vehicle tire, which comprises at least one reinforcement layer according to the invention in the belt and / or in the tread band. It is preferably a tire for passenger cars or a tire for industrial vehicles.

It is advantageous that the reinforcement layer has at least two different reinforcement supports in terms of material and / or structure. It may be at least two cord fabrics that differ, for example, in the material of the threads and / or in the structure of the threads and / p in the fineness of the threads and / or in the combination of threads and / or in the construction of the cord fabric. The reinforcing layer may have, for example, at least one cord fabric of basalt fibers as well as at least one cord nylon fabric. You can also try at least two tapes that

they differ in the material and / or in the cross section of the tape and / or in the number and / or fineness of the

monofilaments and / or the fineness of the tape. The reinforcing layer may have, for example, in addition to at least one tape, at least one other tape containing a plurality of basalt fibers and whose monofilaments are made of nylon. In addition to at least one tape, the reinforcing layer may contain at least one thread or cord fabric. The

Arrangement of the different reinforcement supports in the reinforcement layer may be alternative. Due

The advantages of different reinforcement supports can be combined with the use of different reinforcement brackets.

In the cross section of the reinforcement layer, the reinforcement supports can be oriented approximately parallel. It may be at least two parallel-oriented reinforcement brackets, or a reinforcement bracket that has parallel sections. It can be, for example, a reinforcement support of the tread reinforcement layer of the tread of a tire wound more or less parallel to the circumferential direction of the tire with more than two turns in an area of the belt a along the axial width.

Other features, advantages and details of the invention are described in greater detail in view of the drawings representing schematic embodiments. It looks in the

Figure 1 a partial radial section of a tire:

Figure 2 a cord fabric 20 as a reinforcing support according to the invention;

Figure 3 another cord fabric 20 as a reinforcement support according to the invention;

Figure 4 a cross section of a section of a reinforcing layer 13 containing two tapes 9 according to the invention.

Figure 1 shows the right half of a cross section of a tire for tourism. The fundamental components, of which the tire is composed, are an inner layer 1 largely impermeable to air, a housing 2 that contains at least one reinforcement layer 13 which, usually, arrives from the zenith zone of the tire, through the walls 3, to the areas of flanges 4 containing at least one reinforcement layer 13 as reinforcement of the flanges, being anchored theref around the cores of the traction-resistant flanges 5, a treadmill 6 profile that is radially above the carcass and a belt 7 disposed between the tread 6 and carcass 2, which contains two reinforcing layers 13 and which is covered radially on the outside, in a usual manner, with the reinforcement layer 13 of tread band 8.

In radial construction tires, such as those shown in Figure 1, the reinforcement brackets of the reinforcement layer 13 of the housing 2 are arranged approximately parallel in approximately radial direction 14. The belt 7 has two reinforcement layers 13 largely superimposed, the reinforcing supports being oriented in the different layers respectively in a more or less parallel way. The direction of development of the reinforcement supports in the two reinforcement layers 13 is in one of the layers ascending at an acute angle towards the tire gauge in one of the directions, and in the other layer ascending at an acute angle to the tire gauge In the other direction. The reinforcement layer 13 of the tread band 8 comprises a reinforcement support continuously wound along the axial width.

Figure 2 shows a cord fabric 20 for a reinforcement layer 13 according to the invention. The cord fabric 20 is formed by two threads 21 having monofilaments 11. The monofilaments 11 of the threads 21 are basalt fibers. The fineness of the threads 21 is respectively 1000 dtex. The threads are subjected to a first twist with 50 t / m respectively in the S direction and a final twist with 50 m / t in the Z direction. The basalt fibers are provided with a viral functionalization as well as an RFL adhesion impregnation. The cord 20 fabric is also provided with an RFL adhesion impregnation.

Figure 3 shows another cord fabric 20 for a reinforcement layer 13 according to the invention. The cord 20 fabric is formed by two threads 21a and 21b subjected to a final twist of 75 t / m in the S direction. The monofilaments 11 of the thread 21a are PA 6.6. They have undergone a first torsion of 100 t / m. The thread 21a has a fineness of 940 dtex. The monofilaments 11 of the thread 21b are made of basalt fibers. They have undergone a first torsion of 75 t / m. The thread 21b has a fineness of 1000 dtex. The basalt fibers 11 of the thread 21b have been chemically activated, the cord fabric 20 is provided with an RFL adhesion impregnation.

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Figure 4 shows a cross section of a section of the reinforcement layer 13 according to the invention containing two tapes 9 as reinforcement supports embedded in an elastomeric material 10. The plane of the cross section is, in this case, perpendicular to the direction of longitudinal extension of the tapes. The monofilaments 11 of the tapes 9 are basalt fibers. For clarity, only a small number of basalt fibers is shown in Figure 2. Basalt fibers 11 are provided with an epoxy functionalization and are held together by means of a crosslinkable resin as an adherent agent 12. Adhesive agent 12 represents 4% by weight of the tapes 9. The tapes 9 have a fineness of 1300 dtex and an amount of 1000 filaments 11. The height of the cross section a meets the condition a = 90 ^ m, the ratio between the width of the cross section b and the height of the cross section a meets the condition b / a = 15. The belts 9 are provided with an RFL-Dip adhesion impregnation.

Reference List

(Part of the description)

1 inner layer

2 Housing

3 Side wall

4 Flange area

5 Core of flanges

6 Tread

7 Strap

8 Tread band

9 Tape

10 elastomer material

11 Monofilament

12 Bonding Agent

13 Reinforcement layer

14 Radial Direction

15 Axial Direction

20 Cord fabric

21 thread

21st Thread

21b Thread

a Height of the cross section of the belt

b Width of the cross section of the belt

Claims (10)

5 10 fifteen twenty 25 30 35 40 Four. Five 1. Reinforcement layer (13) for vehicle tires, preferably for tread band (8) or belt (7) of a tire, comprising at least one reinforcement support embedded in an elastomeric material ( 10) which has a plurality of monofilaments (11), characterized by a plurality of monofilaments (11) of the reinforcing support are basalt fibers. 2. Reinforcement layer (13) according to claim 1, characterized in that basalt fibers contain at least 90% by weight, especially at least 95% by weight, especially 100% by weight of natural basalt. 3. Reinforcement layer (13) according to at least one of the preceding claims, characterized in that all monofilaments (11) of the reinforcement support are basalt fibers. 4. Reinforcement layer (13) according to at least one of the preceding claims, characterized in that the reinforcement support has a plurality of monofilaments (11) of non-basaltic material. 5. Reinforcement layer (13) according to at least one of the preceding claims, characterized in that the reinforcement support has a plurality of monofilaments (11) of raw materials that grow back completely or at least in part, especially of chemical fibers based on cellulose and / or natural fibers. 6. Reinforcement layer (13) according to at least one of the preceding claims, characterized in that basalt fibers are provided with an epoxy and / or vylic functionalization. 7. Reinforcement layer (13) according to at least one of the preceding claims, characterized in that the reinforcement support is a cord fabric of at least one thread, said thread having a plurality of basalt fibers. 8. Reinforcement layer (13) according to at least one of claims 1 and 2, characterized in that the reinforcement support is a tape (9) whose cross section meets the condition a <b, defining the height of the cross section and b the width of the cross section of the tape (9), whereby the tape ( 9) is arranged in the reinforcement layer (13) so that the extension direction of b is oriented approximately parallel to the surface extension of the reinforcement layer (13), because the tape (9) contains a plurality of monofilaments (11) arranged more or less parallel to the longitudinal extension of the tape (9), the monofilaments (11) being held together within the tape (9) by means of an adherent agent (12), and by which a plurality of monofilaments (11) are basalt fibers. 9. Reinforcement layer (13) according to at least one of the preceding claims, characterized in that the basalt fibers and / or the reinforcement support are provided with an adhesion impregnation to guarantee the adhesion between the reinforcement support and the elastomeric material (10). 10. Vehicle tire comprising at least one reinforcement layer (13), especially a reinforcement layer (13) of the belt (7) and / or tread band (8), according to at least one of the preceding claims.